Abstract
This paper presents empirical evidence regarding the nature of our commonsense concept of belief. The findings have significant bearing upon claims made by authors concerned with the Folk Psychology Debate - in particular, they challenge Stephen Stich's (1983) claims that folk psychology is committed to a broad account of belief states. In contrast it is found that folk psychology favours a narrow account of belief. This result is important in refuting Stich's claim that the folk psychological concept of belief has no role to play in a developed cognitive science. The paper also presents evidence regarding the influence of several factors on folk psychological judgements of belief individuation (emphasised similarities/differences between the referents of beliefs, nature of past beliefs, goal of classification), and introduces a methodology by which to investigate further factors. It is argued that the observed conflict between individual speculations about likely folk psychological intuitions within the philosophical literature and actual empirical data regarding subjects' responses highlights the important contribution of experimental psychology in exploring such philosophical issues.